U.S. Pat. No. 4,622,727 discloses a seat belt buckle having a spring biased ejector member. The buckle further comprises a base, a pushbutton member, and a lock bar. The lock bar is supported for vertical movement into and out of a position in which it extends across a horizontal track within the base. The ejector member is supported from horizontal movement along the track, and is spring biased into a position in which it blocks entry of the lock bar into the track. When a seat belt locking tongue is inserted into the buckle, the leading edge of the locking tongue engages the ejector member. The locking tongue slides the ejector member along the track against the bias of a coil spring. When the locking tongue is fully inserted into the buckle, the ejector member is moved out of the path of movement of the lock bar so that the lock bar can move vertically into the track under the influence of a leaf spring. When extending across the track, the lock bar engages the locking tongue to hold the locking tongue in the buckle. When the locking tongue is to be released from the buckle, the vehicle occupant pushes the pushbutton member to slide it along the base toward an unlocking position. Cam surfaces on the pushbutton member then lift the lock bar out of the track and out of engagement with the locking tongue. The ejector member then slides along the track against the leading edge of the locking tongue under the influence of the coil spring and ejects the locking tongue from the buckle.
In the '727 buckle, the pushbutton member is connected to the coil spring through the ejector member. The coil spring thereby resists sliding movement of the pushbutton member toward the unlocking position, and can move the pushbutton member back from the unlocking position to its original position. For this purpose, the pushbutton member includes an elongated narrow plastic piece extending from the center of the pushbutton member. The plastic piece has a free end in abutting contact with the free end of a narrow plastic piece which extends from the center of the ejector member. The narrow plastic pieces can experience shrinkage during molding. As a result, the pieces may be misaligned when assembled together. If misaligned, the pieces could deflect relative to each other and become wedged together. The pushbutton member and the ejector member would thus be wedged together, and the buckle would be inoperative.